* Do backslash escape parsing in parse_kv() [was being done in the copy
module purely for newlines in the copy module's content param before]
* Make parse_kv always return unicode
* Add bandaid to transform args to unicode until we can fix things
calling parse_kv to always send it unicode.
* Make split_args deal with unicode internally. Warning, no bandaid for
things calling split_args without giving it unicode (shouldn't matter
as dealt with str internally before)
* Fix copy and unarchive action plugins to not use setdefaultencoding
* Remove escaping from copy (it was broken and made content into latin-1
sometimes). escaping is now in parse_kv.
* Expect that content is now a unicode string so transform to bytes just
before writing to the file.
* Add initial unittests for split_args and parse_kv. 4 failing
tests.because split_args is injecting extra newlines.
